<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<input type="text" id="input">
<button id="111">注册</button>
<script src="../../../javascript/work/2/判断用户名是否合法.js"></script>
</body>
</html>